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 PARENT SESSION
3C - Fate and effects of TBT
Poster Hall
8:30 AM - Wednesday, 30 April 2003
(WEP/172) Butyltin and Mercury in harbour porpoises from Danish waters and West Greenland.
Strand, Jakob1, Larsen, Martin M.1, Lockyer, Christina2, 1 National Environmental Research Institute, Roskilde, Denmark, Denmark2 Danish Institute of Fisheries Research, Charlottenlund, Denmark, Denmark
ABSTRACT- The concentrations of mercury and the antifouling agent tributyltin (TBT) and its breakdown products, dibutyltin (DBT) and monobutyltin (MBT), were measured in liver samples of 38 harbour porpoises (Phocoena phocoena) from the Inner Danish waters, the eastern North Sea and West Greenland. The concentration of butyltin and mercury in harbour porpoises from Danish waters varied between 68 - 4605  g/kg ww and 0.22 - 92.0 mg/kg ww, respectively. In the samples from West Greenland the butyltin concentration was found to be between 2.0 and 18 g/kg ww. This indicates that TBT is also spread into the Arctic marine environment. The butyltin concentrations found in harbour porpoises from Danish waters, are the highest levels described in literature for this coastal cetacean. The mercury concentration in harbour porpoises from West Greenland was comparable with the concentrations found in Danish waters. Both butyltin and mercury were found to accumulate with age and size. Especially mercury tented to accumulate in the liver through out the life span. No sexual differences in concentration levels were found. Statistical analyses revealed that stranded harbour porpoises had accumulated higher levels of butyltins than harbour porpoises caught as by-catch by fishermen, also after normalisation with age which is a confounding factor. This difference might be related to effects on the health status but it may also be due to differences in feeding habits between by-caught and stranded harbour porpoises.
Key words: Mercury, Tributyltin, Harbour porpoise, Denmark
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